Balázs, M., and G. Goldner. “On the Approximative Solving of the Integral Equations”.
Anal. Numér. Théor. Approx.
, vol. 6, no. 1, Feb. 1977, pp. 5-7,
https://ictp.acad.ro/jnaat/journal/article/view/1977-vol6-no1-art1
.